Chapter 9, Problem 1Q

To determine

The reason behind the opposite direction of orbital angular momentum and magnetic moment of electron.

Answer to Problem 1Q

The direction of magnetic moment and orbital angular momentum of a charged particle depends upon the polarity of the charge on the charged particle. The electron is a negatively charged particle due to which the direction of magnetic moment is opposite to that of the direction of orbital angular momentum.

Explanation of Solution

The orbital angular moment of an electron arises due to the motion of the electron about its nucleus. The orbital angular momentum is rotational variant of linear angular momentum.

The magnetic moment or magnetic dipole moment of an electron arises due to the intrinsic properties of electron mainly charge and spin.

Write the expression for the magnetic moment of a charged particle.

  $\mu =\frac{q}{2m}L$        (I)

Here, $\mu$ is the magnetic moment, $q$ is the charge present on the charged particle, $L$ the orbital angular momentum and $m$ is the mass of the charged particle.

The direction of magnetic moment and orbital angular momentum of a charged particle depends upon the polarity of the charge on the charged particle. The electron is a negatively charged particle due to which the direction of magnetic moment is opposite to that of the direction of orbital angular momentum.

Conclusion:

Thus, the direction of magnetic moment and orbital angular momentum of a charged particle depends upon the polarity of the charge on the charged particle. The electron is a negatively charged particle due to which the direction of magnetic moment is opposite to that of the direction of orbital angular momentum.